Davit



Dec. 23, 1924. 1,520,087 A. P. SCHAT a DAVI '1 Filed Dec. 26. 1919 2Sheets-Sheet 1 INVENTOR.

A. P. SCHAT DAVIT Filed Dec. 26. 1919 2 Sheets-Sheet 2 I N VEN TOR.

A TTORNE Y.

Patented Dec. 23, 1924,

UNITED STATES ANE P. SCI-IA'I, OF U'IEECHT, NETHERLANDS.

DAVIT.

Application filed December 26, 1919. Serial No. 347,637.

To all whom it may concern:

Be it known that I, Alva P. SoHA'r, a citizen of the Kingdom of theNetherlands, residing at Utrecht, and Kingdom of the Netherlands, haveinvented certain new and useful Improvements in Davits, of which thefollowing is a specification.

My invention relates to ships" davits, and more particularly to thatclass of davits which is adapted to swing lifeboats overboardautomatically.

My objectis to provide a pair of automatic rotatable davits located atthe outer side of the boat, and adapted to allow one end of the boat toswing out in advance of the other, without either end contacting withthe davits, whereby a boat longer than the distance between the davitsmay be used.

Another object is to provide a pair of davits for a lifeboat, with oneor both davits inclined and otherwise so arranged and constructed thatone of the davits will operate by gravity in advance of the other andwill move through a considerable angle before the other has moved amaterial distance from its starting point, thereby prolonging the periodof action of the davits in swmging a boat overboard, in order to givethe slowest possible movement of the boat with any given inclination ofdavit.

A further object is to provide a pair of davits so constructed andarranged that both davits may be made to act automatically to swing alifeboat overboard, or that only one of the davits will. actautomatically, but in doing so will also operate the other davit.

Other objects will appear in the subjoined description, reference beinghad to the accompanying drawings, in which F igs. 1, 2, and 3,illustrate diagrammatically an embodiment of the invention in a sideelevational view, an end view, and a plan view, respectively.

Fig. 4- illustrates a series of davits mounted in stationary framessecured on ships deck, with the axes of rotation of the davits havingpermanent inclination outward, each frame here serving as a support fortwo adjacent davits.

Figs. 5 and 6, illustrate, on an enlarged scale, said double frame inside elevation and plan View respectively, together with the brakemechanism employed with the davits.

The lifeboat 1 is suspended by means of tackles 2, 3, from rota-tabledavits 4;, 5, supported by cup bearings preferably mounted on the sideof the ship. The davit 4 (see Fig. 2) has its axis of rotation disposedat a considerable inclination outwardly, the axis of davit 5 beingvertical, assuming the ship to lie normally in horizontal position onthe water.

The distance between said da-vits is less than the length. between theboats.

hen the boat and the davits 4-, 5, are in the position shown in fulllines, the boat swings below the davit heads after it is cleared of thechocks. Owing to this motion, the point at which the tackle 2 isattached to the boat descends, while that of the tackle 3 remains atsubstantially the same level. Under the action of gravity the boat willtherefore move to the right hand side, that is to say, towards the davit5, whereby the boat will assume the position 1 shown in dotted lines. Atthe same time, however, the davit t commences to swing around about itsaxis of rotation, whereby the boat clearing this davit, will move to thefurther position 1*. Up to this point the davit 5 has not turned throughany appreciable angle, but from-this position onward, the system movesoutward by gravity, i. e., the davit 4 with the boat suspended therefromexerts a pull on the davit 5, whereby the rear end. of the boat movesclear of davit 5 until the boat finally reaches its extreme outboardposition 1.

In order to facilitate the inboard movement of the boat when it isdesired to stow it upon its chocks, the davit 4 is preferably coupledwith means by which its inclination toward the side of the ship may bevaried, and allowing the davit to be set with its axis of rotationinclining inwardly, saidmeans being diagra-mmatically shown in Fig. 2,and consisting of a horizontal pipe 6 mounted for longitudinal movementin a post 6*, said pipe being provided at its outer end withbifurcations 6 (see Figs. 1 and 2) which are pivotally connected to theopposite sides of a collar 6" carried by the davit, and within which thedavit rotates, while at its inner end this pipe is internally threadedto receive a cooperating threaded bar 6 which is rotated by a hand wheel6 supported in a post 6, whereby the internally threaded pipe 6 and thethreaded bar 6 form means for adjusting the davit 4 to outward or inwardinclination.

Means for regulating the inclination of the davit are not claimedbroadly herein, since such means are described and claimed in thespecification of my copending application No. 286,018.

As it should be possible to swing the boat outboard in case of the shiphaving a heavy list, davit 5 may also be provided with means allowingits axis of rotation to be disposed at varying inclinations relativelyto the ships side, so that one davit may always be given a true verticalposition while the other has its axis of rotation suitably inclinedoutwards.

It should be understood that I may also mount both davits with theiraxes of rotation under equal or unequal inclinations outwardly. In orderthat the boat in this case may be swung outboard it may be necessary toinitially prevent the one davit from rotating, for instance by brakemeans, and to release it after the other davit has swung outboard aboutits axis.

In the arrangement shown in Figs. 1 to 3, the lifeboat would collidewith both davits if while extending in longitudinal parallelism with theship it had freedom to move laterally outward in a line at right anglesto said direction. The arrangement may however be such that only onedavit assumes the inclined position, the other being cleared when theboat moves as stated above, (see Fig.

According to Fig. at, all the davits are mounted in stationaryframes 7secured on deck, so that their axes of rotation have permanentinclination outwards, each frame here serving for supporting twoadjacent davits. Figs. 5 and 6 illustrate the said double frame in sideelevation and in plan view respectively.

Each davit is provided with a brake disc 8 having a brake band 9 thereonadapted to be tightened and released by a screw actuated by a hand wheel11.

It should be noticed that with the arrangement shown in Fig. 4 it is notstrictly necessary to initially prevent one davit from rotating when itis desired to swing the boat outboard in the manner specified, since inthe outset, one end of each boat is free to move laterally outward andthe other is prevented from doing so by one of the frames till theformer end has advanced a certain distance.

As a matter of course, the arrangements described may be combined andvaried in many respects without departing from the underlying inventiveidea. All the arrangements and variations, however, have the commonfeature that they allow the boats to be placed on deck with very smallinterspacing, and yet permit them to be swung outboard automatically,the movement being controlled, if desired, by simply tightening orreleasing suitable braking mechanism.

It may also be pointed out that with inclined davits, ditliculty isoften experienced in preventing the boats from moving out too suddenly,especially if the boat has an unusually heavy load, or if the ship has alist in the direction of the outboard movement.

l Vith my present arrangement in which one davit moves in advance of theother, the davits, to a certain extent, operate one at a time, so thatin their outward movement the advance davit has reached and passed thepoint at which it moves with the greatest force before the other davithas reached the corresponding position in its outward movement. Hence,the force which causes the davits to rotate is more evenly distributedand extends over a longer period of time than if each davit exercisedits maximum power of rotation at the same time.

Again it has been found that inclined davits have a tendency to swingout so sud denly overboard that it is impossible to operate the brakemechanism quick enough to catch the davits, so to speak, before they arealready out.

lVith my present construction it will be seen that by applying a braketo the tardy davit, it will be a very easy matter to have the systemunder control of the brake before the boat has moved far outboard.Moreover, even if the lock be applied to the advance davit, the factthat the outward movement of, the boat is distributed over a longerperiod of time, will give better opportunity to operate the brake, thanin any case where both davits move out together.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is 1. In a device of the character described, apair of rotatable davits arranged to swing a lifeboat overboard one endin advance of the other, one of said davits being arranged to swingoutwardly by gravity to cause it to act automatically, and the otherdavit being free to rotate but not adapted within itself to rotate bygravity.

2. In a device of the character described, a pair of rotatable davitsarranged at the outer side of a lifeboat to swing out over the water,one of said davits being arranged to swing outwardly by gravity torender the same automatic in its outward movement, and the other davitbeing free to rotate but not adapted within itself to rotate by gravity,said gravity-actuated davit being arranged to travel ahead of the otherdavit as the two go outboard.

3. In a device of the character described, a pair of rotatable davitsarranged at the outer side of a lifeboat, said boat being suspendedtherefrom and connecting the two davits together, said davits beingdisconnected from each other except by the suspended boat, one of thedavits being arranged to swing outwardly by gravity to render itautomatic in its outboard move ment, and the other davit being free to1'0- tate, but not adapted within itself to rotate by gravity, theautomatic davit traveling in advance of the other davit as the two gooutboard; and means for regulating the automatic action of the gravitydavit.

4. In a device of the character described, a pair of rotatable davitsfor swinging a lifeboat overboard, said davits being arranged oneadjacent each end of the boat, one of said davits having its axis ofrotation normally inclined to cause the davit to swing by gravity to itslowermost position to render the davit automatic, and the other davithaving its axis of rotation nor mally vertical and therefore not adaptedwithin itself for automatic rotation; a flexible connection between eachdavit and its respective end of the boat, whereby to utilize the boatand said flexible connections to form a yielding connection between thetwo davits to control the outward rotation of both davits by theautomatic davit; and means for regulating the automatic action of thegravity davit.

5. In a device of the character described, a pair of rotatable davitsfor swinging loads overboard, one of said davits being adapted to rotateby gravity and the other davit not adapted to rotate by gravity; meansfor yieldingly connecting said davits together, whereby the tendency ofthe one davit to rotate by gravity is yieldingly communicated to theother davit which of itself does not tend to rotate by gravity; andmeans for regulating the automatic action of the gravity davit.

6. In a device of the character described, a pair of rotatable davitsarranged at the outer side of a lifeboat closer to each other than thelength of the boat, one of said davits having its axis of rotationnormally inclined outwardly to cause the davit to swing overboard bygravity, and the other davit being vertical andnot adapted to be swun gout by gravity; and means for varying the degree of axial inclination ofthe inclined davit and for changing the direction of its inclinationfrom an outward in clination to an inward.

7. In a device of the character described, a pair of rotatable davitsarranged at the outer side of a lifeboat and spaced apart a distanceless than the length of the boat, one of said davits being vertical andnot adapted to rotate by gravity, and the other being inclined outwardlyto cause it to retate overboard by gravity and having its jib extendinginwardly diagonally across the boat in a direction to cause it to rotateoutwardly ahead of the vertical davit when the boat is released from itschocks and hangs suspended from the davits, whereby to cause saidinclined davit in its initial outward movement to swing the boatlongitudinally toward the vertical davit, to cause the end of the boatsupported by the inclined davit to clear said davit, and whereby to alsoretard the outward movement of the vertical davit till the end of theboat supported by the inclined davit has moved outwardly past its davit;and means for varying the inclination of the inclined davit.

In testimony whereof I aflix my signature.

AYNE P. SCHAT.

